x86: simplify the management of binding hooks

We check early whether binding is available, record the thread or proc
support there, and just use that one later, instead of trying both.

diff --git a/src/topology-x86.c b/src/topology-x86.c
index d451a059034f9c3f15f18e571beef82b9f52a8e3..87ef067bfe9deec05f2133bb23d9baaf023167c8 100644 (file)
--- a/src/topology-x86.c
+++ b/src/topology-x86.c
@@ -794,15 +794,27 @@ int hwloc_look_x86(struct hwloc_topology *topology, unsigned nbprocs, int fulldi
   struct hwloc_binding_hooks hooks;
   struct hwloc_topology_support support;
   struct hwloc_topology_membind_support memsupport __hwloc_attribute_unused;
+  int (*get_cpubind)(hwloc_topology_t topology, hwloc_cpuset_t set, int flags);
+  int (*set_cpubind)(hwloc_topology_t topology, hwloc_const_cpuset_t set, int flags);
   int ret = -1;
 
+  /* check if binding works */
   memset(&hooks, 0, sizeof(hooks));
   support.membind = &memsupport;
   hwloc_set_native_binding_hooks(&hooks, &support);
-  if (nbprocs > 1 &&
-      !(hooks.get_thisproc_cpubind && hooks.set_thisproc_cpubind)
-   && !(hooks.get_thisthread_cpubind && hooks.set_thisthread_cpubind))
-    goto out;
+  if (hooks.get_thisproc_cpubind && hooks.set_thisproc_cpubind) {
+    get_cpubind = hooks.get_thisproc_cpubind;
+    set_cpubind = hooks.set_thisproc_cpubind;
+  } else if (hooks.get_thisthread_cpubind && hooks.set_thisthread_cpubind) {
+    get_cpubind = hooks.get_thisthread_cpubind;
+    set_cpubind = hooks.set_thisthread_cpubind;
+  } else {
+    /* we need binding support if there are multiple PUs */
+    if (nbprocs > 1)
+      goto out;
+    get_cpubind = NULL;
+    set_cpubind = NULL;
+  }
 
   infos = calloc(nbprocs, sizeof(struct procinfo));
   if (NULL == infos)
@@ -854,22 +866,12 @@ int hwloc_look_x86(struct hwloc_topology *topology, unsigned nbprocs, int fulldi
 
   hwloc_x86_os_state_save(&os_state);
 
-  if (hooks.get_thisthread_cpubind && hooks.set_thisthread_cpubind) {
-    /* trying binding the current thread only */
-    ret = look_procs(topology, nbprocs, infos, fulldiscovery,
-                    highest_cpuid, highest_ext_cpuid, features, cpuid_type,
-                    hooks.get_thisthread_cpubind, hooks.set_thisthread_cpubind);
-    if (ret < 0) {
-      /* fallback trying to bind the entire process */
-      if (hooks.get_thisproc_cpubind && hooks.set_thisproc_cpubind)
-       ret = look_procs(topology, nbprocs, infos, fulldiscovery,
-                        highest_cpuid, highest_ext_cpuid, features, cpuid_type,
-                        hooks.get_thisproc_cpubind, hooks.set_thisproc_cpubind);
-    }
-    if (ret >= 0)
-      /* success, we're done */
-      goto out_with_os_state;
-  }
+  ret = look_procs(topology, nbprocs, infos, fulldiscovery,
+                  highest_cpuid, highest_ext_cpuid, features, cpuid_type,
+                  get_cpubind, set_cpubind);
+  if (ret >= 0)
+    /* success, we're done */
+    goto out_with_os_state;
 
   if (nbprocs == 1) {
     /* only one processor, no need to bind */